Employees working in areas where electrical hazards are present shall be provided with, and shall use, protective equipment that is designed and constructed for the specific part of the body to be protected and for the work to be performed.Personal Protective Equipment
- General : When an employee is working within the Flash Protection Boundary he/she shall wear protective clothing and other personal protective equipment in accordance with NFPA 70E.
- Movement and Visibility : When flame-resistant (FR) clothing is worn to protect an employee,it shall cover all ignitable clothing and shall allow for movement and visibility.
- Head, Face, Neck, and Chin Protection : Employees shall wear non-conductive head protection wherever there is a danger of head injury from electric shock or burns due to contact with live parts or from flying objects resulting from electrical explosion. Employees shall wear non-conductive protective equipment for the face, neck, and chin whenever there is a danger of injury from exposure to electric arcs of flashes or from flying objects resulting from electrical explosion.
- Eye Protection : Employees shall wear protective equipment for the eyes whenever there is danger of injury from electric arcs, flashes, or from flying objects resulting from electrical explosion.
- Body Protection : Employees shall wear FR clothing wherever there is possible exposure to an electric arc flash above the threshold incident-energy level for a second-degree burn. 5 J/cm2 (1.2 cal/cm2). Such clothing can be provided as shirt and trousers, or as coveralls, or as a combination of jacket and trousers, or, for increased protection, as coveralls with jacket and trousers. Various weight fabrics are available. Generally, the higher degree of protection is provided by heavier weight fabrics and/or by layering combinations of one or more layers of FR clothing. In some cases one or more layers of FR clothing are worn over flammable, non melting clothing. Non-melting, flammable, clothing, used alone, can provide protection at low incident energy levels of 8.36 J/cm2 (2.0 cal/cm2) and below.
- Hand and Arm Protection : Employees shall wear rubber insulating gloves where there is danger of hand and arm injury from electric shock due to contact with live parts. Hand and arm protection shall be worn where there is possible exposure to arc flash burn.
- Foot and Leg Protector : Where insulated footwear is used as protection against step and touch potential,dielectric overshoes shall be required. Insulated soles shall not be used as primary electrical protection.
- Selection of Personal Protective Equipment : When Required for Various Tasks When selected in lieu of the flash hazard analysis, NFPD table 130.7(C)(9)(a) shall be used to determine the hazard risk category for a task. The assumed short-circuit current capacities and fault clearing times for various tasks. Systems with greater than the assumed fault clearing times, a flash hazard analysis shall be required.
Factors in Selection of Protective Clothing
Clothing and equipment that provide worker protection from shock and arc flash hazards shall be utilized. Clothing and equipment required for the degree of exposure shall be permitted to be worn alone or integrated with flammable , non melting apparel. If FR clothing is required, it shall cover associated parts of the body as well a all flammable apparel while allowing movement and visibility.
All personal protective equipment shall be maintained is a sanitary and functionally effective condition. Personal protective equipment items will normally be used in conjunction with one another as a system to provide the appropriate level of protection.
- Layering
- Non melting, flammable fiber garments shall be permitted to be used as under layers in conjunction with FR garments in a layered system for added protection. If non melting, flammable fiber garments ate used as under layers the system arc rating shall be sufficient to prevent break open of the innermost FR layer at the expected arc exposure incident energy level to prevent ignition of flammable under layers. A typical layering system might include cotton shirt and trouser, and a FR coverall. Specific tasks might call for additional FR layers to achieve the required protection level.
- Outer Layers
- Garments worn as outer layers over FR clothing, such as jackets or rain wear, shall also be made from FR material.
- Under Layers
- Melt able fibers such as acetate, nylon, polyester, polypropylene, and spandex shall not be permitted. in fabric under layers (underwear) next to the skin.
- Coverage
- Clothing shall cover potentially exposed areas as completely as possible. Shirt sleeves shall be fastened at the wrist, and shirts and jackets shall be closed at the neck.
- Fit
- Tight-fitting clothing shall be avoided. Loose fitting clothing provides additional thermal insulation because of sir spaces. FR apparel shall fit properly such that it does not interfere with the work task.
- Interference
- The garment selected shall result in the least interference with the task but still provide the necessary protection. The work method,location, and task could influence the protective equipment selected.
Care of Equipment
Protective equipment shall be maintained is a safe, reliable condition. The protective equipment shall be visually inspected before each use.
Both larger and smaller available short-circuit currents could result in higher available arc-flash energies. If the available short circuit current increases without a decrease in the opening time of the over current protective device, the arc-flash energy will increase. If the available short-circuit current decreases, resulting in a longer opening time for the over current protective device, arc flash energies could also increase.
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